Abstract: The structure reliability of solid rocket motor grain was analyzed based on Kriging method.Firstly,Lating hypercube sampling was used to get sampling data of random variables.Secondly,the grain structure was analyzed using finite element method with sampling data.At last,a response surface of octahedron shear stress was estimated using Kriging model.And,the reliability of grain was estimated in combination with failure criterion.To evaluate the applicability of the Kriging method,Monte Carlo simulation was employed to compare with it.The approximate results of reliability qualify the performance of the method.